Field
Embodiments of the present disclosure generally relate to a chemical mechanical polishing (CMP) apparatus and methods of making and using the same. More specifically, embodiments described herein relate to techniques for collecting data in a CMP apparatus, such as collecting data relating to a CMP process and/or data relating to a component found in the CMP polishing apparatus.
Description of the Related Art
Chemical mechanical polishing (CMP) is a technique commonly used to planarize substrates during the fabrication of semiconductor devices. During a CMP process, a substrate being processed is mounted on a carrier head with the device surface positioned against a rotating polishing pad. The carrier head provides a controllable load to the substrate to push the device surface against the polishing pad. A polishing liquid, such as a slurry with abrasive particles, is typically supplied to the surface of the polishing pad. Polishing pads are consumable components that typically become worn after polishing a certain number of substrates. Accordingly, the pads, and other CMP consumable components, need to be replaced occasionally to maintain a consistent and suitable polishing performance.
Polishing pads are typically made by molding, casting or sintering polyurethane materials. In the case of molding, the polishing pads can be made one at a time, e.g., by injection molding. In the case of casting, the liquid precursor is cast and cured into a cake, which is subsequently sliced into individual pad pieces. The pad pieces can then be machined to a final thickness. Grooves can be machined into the polishing surface, or be formed as part of the injection molding process. These methods of manufacturing polishing pads are expensive and time consuming. Moreover, polishing pads manufactured by these methods often yield non-uniform polishing results. For example, during CMP, different areas on the substrate may be polished at different rates resulting in too much material removed (“overpolishing”) in some areas or too little material removed (“underpolishing”) in other areas.
In addition, polishing pads and other CMP apparatus manufactured by conventional techniques often lack devices and methods for performing various tracking, sensing, monitoring, and process metrology functions. Conventional CMP systems often rely on system level sensing techniques which typically do not provide enough data to adequately control the CMP processes required to planarize devices formed in advanced technology integrated circuit nodes.
Therefore, there is a need for CMP systems, polishing pads and other CMP apparatus that provide improved polishing performance and desirable process sensing capabilities. In addition, there is a need for methods of manufacturing such apparatus.